Sunday, April 20, 2014

Overcoming the Cold Chain Problem in Vaccine Storage and Distribution

One of the major problems faced during epidemic and pandemic outbreak of disease is overcoming the 'cold chain' issue both in the storage, as well as the distribution of vaccines. Bio-defence vaccines are no different, however, the circumstances of their distribution may increase risks associated with cold chain standards. Imagine a deliberate outbreak of smallpox in a remote village in the Congo or worse during conflict, which poses more extreme obstacles in terms of epidemiological trace-back, delivery of vaccines and ultimately vaccination. While disruptions in the cold chain protocol result in millions of lost dollars and vaccines, future biologicals are swiftly overcoming this problem.

"Cold chain management is the process of preparing temperature-sensitive medical products for shipment utilizing standardized systems and procedures, maintaining required temperatures during all phases of distribution from the time it leaves the manufacturer until administration of the vaccine to the patient. Vaccines are sensitive biological substances that can lose their potency and effectiveness if exposed to heat, extreme cold, and or light. For example, certain vaccines lose potency when exposed to room temperature for as little as 30 minutes and freezing damages almost all refrigerated vaccines. Failure to adhere to proper storage temperatures may reduce vaccine potency, resulting in an inadequate immune response and protection against disease. Once lost, vaccine potency cannot be reversed.

"Roughly 1.5 million children die each year from vaccine-preventable diseases like tuberculosis. This is due in part to the sensitive nature of the vaccines themselves, which spoil if they're not kept at precise temperatures from manufacturing to use. The cold supply chain is well established in many parts of the world, but poor infrastructure and unreliable power prevent vaccines from reaching many developing countries."

Soligenix is a pharmaceutical company manufacturing bio-defence vaccines, but its their 'thermostability technology' which caught my eye. Typically, bio-defence vaccines are vaccines developed to treat the probability of a wide spread outbreak of diseases we generally don't see in annual epidemic outbreaks. These vaccines tend to be more costly to research and develop and investiment in both the U.S. and EU has come, to a large extent, from government agencies (Bio-Shield, BARDA, NIAID). As I wrote my previous pieces on the Ebola outbreak in Guinea and the Strategic National Stockpile, I recalled my engagement some years back with WHO. Vaccine stockpiling and certainly distribution is a core activity during an outbreak of highly pathogenic diseases like we see in Guinea. In this specific case, not only has it been difficult to inspire interest to develop a vaccine candidate against VHF and Crucell (See: has been working on this for years, but the cold chain problem in storage and distribution remains a significant issue. Typically pharmaceutical firms are reluctant to launch into drug development for illness which either do not occur, occur with extremely limited frequency or used only during relatively small outbreaks. Bio-defence vaccines face a number of challenges which vaccine candidates for diseases like mumps, measles and rubella simply do not. Moreover, even in terms of force protection, many of these vaccines are not even on a Milivax schedule for our forces. Added to this, any disruption in the cold chain management of vaccines is a quite serious and significant issue.

I was quite excited when I spotted their announcement that "Recent studies have demonstrated the potential for heat-sensitive vaccines formulated using this technology to withstand temperatures exceeding 40 degrees Celsius (104 degrees Fahrenheit) for up to one year. The underlying work has been conducted with the Company’s proprietary ricin toxin vaccine (RiVax™) as part of a continuing program to evaluate the effectiveness of protein subunit vaccines to withstand extremes of temperature and other environmental stress conditions.(See: Their website states the following: "Soligenix's proprietary thermostability technology, ThermoVax™, is a novel method of rendering aluminum salt, Alum, adjuvanted vaccines stable at elevated temperatures. Alum is the most widely employed adjuvant technology in the vaccine industry. The value of ThermoVax™ lies in its potential ability to eliminate the need for cold-chain production, transportation, and storage for Alum adjuvanted vaccines. This would relieve companies of the high costs of producing and maintaining vaccines under refrigerated conditions. The World Health Organization (WHO) reports that 50% of all vaccines around the world are wasted due to thermostability issues. This is due to the fact that most Alum adjuvanted vaccines need to be maintained at between 2 and 8 degrees Celsius ("C") and even brief excursions from this temperature range (especially below freezing) usually necessitates the destruction of the product or the initiation of costly stability programs specific for the vaccine lots in question. The savings realized from the elimination of cold chain costs and related product losses would in turn significantly increase the profitability of vaccine products. Elimination of the cold chain would also further facilitate the use of these vaccines in the lesser developed parts of the world. On the Vaccines/BioDefense side, ThermoVax™ has the potential to facilitate easier storage and distribution of strategic national stockpile vaccines in emergency settings."

While I would generally review other pharmaceuticals competing in this technology, Soligenix in fact seems to be much further along than others and have a more promising candidate technology. For bio-defence and European/NATO Member State stockpiling, the technology is quite exciting. WHO and Medicine sans Frontiers must certainly be waiting in the wings.

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